Apparatus for continually measuring the temperature of a continuously cast metal rod

ABSTRACT

A method and apparatus for continuously measuring the temperature of a metal rod which is continuously cast and as the rod is fed away from its associated casting mold includes a rotating cylinder or wheel having a plurality of temperature sensors arranged at spaced locations around the circumference which engage against the rod at one or more particular locations. The temperature which is sensed is advantageously transmitted either by wire or radio wave to a control station where the information is employed for the regulation of the feeding and molding and subsequent forming of the continuously cast rod. The device advantageously includes an electrical temperature feeler having one feeler element which is adapted to be connected to a segmental contact and another feeler element adapted to be connected to another segmental contact within the cylinder which moves with its circumference in engagement with a side of the cast rod which is formed. A electrical circuit is provided with means for determining the maximum temperature of each of the feeler elements or a specific temperature as desired and for amplifying the indicated value in transmitting it to a control station as desired. The cylinder may be arranged to roll against the rod, for example, at the location of the so-called sump tip at which the entire rod cross sections begins to solidify.

United States Patent 1 Baumann et al.

' 11 3,731,536 51 May8, 1973 [54] APPARATUS FOR CONTINUALLY MEASURINGTHE TEMPERATURE OF A CONTINUOUSLY CAST METAL ROD [75] Inventors: Hans G.Baumann, Duisburg; Heinz Dietrich Schneider, Rheinhausen, both ofGermany [73] Assignee: DEMAG Aktiengesellschatt, Duisburg, Germany [22]Filed: Nov. 13, 1969 [21] Appl. No.: 876,379

[30] Foreign Application Priority Data Dec. 7, 1968 Germany ..P 18 13330.7

[52] U.S. Cl. ..73/35l, 73/359, 136/221, 164/154 [51] Int. Cl. ..B22d1/02, GOlk 7/02, GOlk 13/06 [58] Field of Search ..73/351, 359; 164/4,164/154; 136/221 [56] References Cited UNITED STATES PATENTS 3,534,61010/1970 Pruden ..73/359 2,206,930 7/1940 Webster ...l64/278 X 2,466,1374/1949 Vollrath .....73/359 X 2,752,411 6/1956 Walter 73/359 X 2,818,732l/1958 Bennett ..73/351 X 3,246,519 4/1966 Domberger.. .....73/359 X3,333,476 8/1967 Hardy et a1 ..73/362 3,358,743 12/1967 Adams 164/1543,364,979 1/1968 Carton ..164/l54 M0402 1 jaw/ v 4 Primary ExaminerLouisR. Prince Assistant Examiner-Frederick Shoon AttorneyMcGlew and Toren[57] ABSTRACT A method and apparatus for continuously measuring thetemperature of a metal rod which is continuously cast and as the rod isfed away from its associated casting mold includes a rotating cylinderor wheel having a plurality of temperature sensors arranged at spacedlocations around the circumference which engage against the rod at oneor more particular locations. The temperature which is sensed isadvantageously transmitted either by wire or radio wave to a controlstation where the information is employed for the regulation of thefeeding and molding and subsequent forming of the continuously cast rod.The device advantageously includes an electrical temperature feelerhaving one feeler element which is adapted to be connected to asegmental contact and another feeler element adapted to be connected toanother segmental contact within the cylinder which moves with itscircumference in engagement with a side of the cast rod which is formed.A electrical circuit is provided with means for determining the maximumtemperature of each of the feeler elements or a specific temperature asdesired and for amplifying the indicated value in transmitting it to acontrol station as desired lhecylinder may be arranged to roll againstthe rod, for example, at the location of the so-called sump tip at whichthe entire rod cross sections begins to solidify.

9 Claims, 4 Drawing Figures APPARATUS FOR CONTINUALLY MEASURING THETEMPERATURE OF A CONTINUOUSLY CAST METAL ROD SUMMARY OF THE INVENTIONThis invention relates in general to a method and apparatus for treatingand controlling the formation of continuously cast metal rods and inparticular, to a new and useful method and device for continuouslymeasuring the temperature of a metal rod as it is being cast and fortransmitting the measurement information, for example, to a controlstation for regulating the treatment of such rods particularly thetreatment of cast steel rods.

Surface temperatures above 700C can be measured without majorexpenditure and up to a temperature range of about 2,000C by radiationpyrometry. The moving measuring object presents only difficultiesinsofar as its surface is covered with scale. The temperatures of metalrods in rolling mills which are measured by radiation pyrometry are thusnot always produced without distortion. In the entire technology adevice for certain purposes has certain qualities. Requirements goingbeyond these are no longer within the range of application of such adevice. In the measurement of surface temperatures of sheet metal thedifferences with respect to the interior of the metal and the exteriorare not so great, so that it is not possible to conclude from theoutside temperature the conditions of the inside temperature. As far asthe mean temperature is thus in a range favorable for radiationpyrometric measurements, the use of such measuring methods can berecommended.

If each measuring object which is covered with a surface scale isalready subject to a natural urge to change constantly, the surfacetemperatures and smaller regions and the conditions inside the largecross sectional surfaces of the core are even more difficult to observe.This situation appears in rolling mills or/and on blooming mill trainswhere holes are driven into the cold iron slabs into which areintroduced specially designed thermocouples. The thermocouples provideinformation for operating pusher type furnaces with a different heatingof the top and the underside which is important for the rolling millprocess. With such a situation and with other rod formations theso-ealled temperature profile is important, that is, the temperaturerise from the inside to the outside of the rod. The most pronouncedexample of such temperature difference from the inside to the outside isa cast rod which is produced in a continuous metal casting plant, and,of this type, particularly cast steel rods of any chemical compositionand alloy steels or refined steels.

The temperature in the rod forms the starting point for the detachmentin the continuous casting mold, for the bending and guiding and thus thefeeding of the rod and also for subsequent straightening in the case ofarcuate or deflection straightening machines. The temperature profile iseven more important in rod forming. Because of the greatly varyingtemperatures, the state of the rod varies in the temperature ranges fromsolid, a mixing zone of solid-liquid, and liquid. Deformations can onlybe carried out safely when the entire cross section is in the hotforming range like the material in a hot rolling mill, for example.

Although a completely balanced temperature profile can hardly beachieved, the knowledge of the actual temperature course is apre-requisite for further treatment and for the operation of the castingdevice. For continuous casting operations attempts have been made todetermine the length of the sump of the liquid rod core by calculationand by pyrometric measurement. The heat potential stored in the interiorof the rod suffers a considerable drop by the outer partly solidifiedpart but it can be assumed that if the inner high potential were missingthe rod shell could not heated to the same extent. The size of the innerheat potential determines therefore the temperature of the rod shellover the transmission ratio. There is another factor which depends onthe chemical composition of the casting material where the differencesin the thermal conductivity of the solidified part can be seen. Sincethe thermal conductivity of the material varies, in addition, with itstemperature range this variation must be taken into consideration unlessof course a stationary state is established after some time and thetemperature measurement is effected at the same point of the rod.

The pyrometric measuring method is based substantially on the radiationemitted by the preheated body. It thus measures the surface temperature.The temperature of the layer underneath the scale layer can differconsiderably from the surface temperature value. This scale layer canalso be irregular in its thickness. In addition under the scale layerthere can be cavities or voids. The oxide films can have differentradiating powers depending on the forming conditions. At the boundary oflayer of the oxide metal the conditions of the heat passage areparticularly difficult to measure and appraise. Calibrations can onlyeliminate those errors to a limited extent.

Other pyrotechnical measurements have sources of error because a desiredconduction and guidance of the heat carrier cannot take place withoutcontact. Upon contact however, the heat conduction is such in most casesthat the measuring result is decisively falsefied.

The present invention is based on the problem of effecting thecontinuous measurement of temperature on metal rods particularly caststeel rods during the casting thereof. The particular difficulty is thatthe measurement must be effected on the moving rod and also that theproblem of the scale layer must be solved. A further difficulty thatcould not be overcome up to the present time is the necessity totransmit the measured values to a remote location for the control of thecasting and forming.

In accordance with the present invention, it is suggested that the abovedifficulties can be eliminated by bringing a cylinder into rollingcontacting engagement with the rod which is being formed at least at onepoint along the length of the rod path of movement and at least on onecross sectional side of the rod. The amount of heat flowing into thecylinder or the resulting temperature is measured and the measuredvalues are transmitted continuously by either wire conductors or bywireless transmitters such as radios to a receiving station which is setup for influencing the regulation of the casting operation. The controladvantageously includes means for regulating and controlling the castingand or the feeding through the feeding machine and/or the regulation ofthe adjustment of the rolls for the rod forming.

A temperature sensing cylinder can be brought into contact with thecontinuously cast rod in many ways. It is possible to compress thecylinder against the scale layer in order to measure the temperature indirect contact with the rod. After a certain starting time, the exacttemperature is obtained and no further delay of the measurement isnecessary because the measured values can be transmitted by a radiotransmission without delay to the control station receiving them. Incontrast to the known state of technology it is thus possible to usecontrol quantities with less errors in order to control the entire plantoperation. The advantage regarding the casting, cooling and feeding andstraightening or forming of the rod are considerable.

In accordance with the a preferred method of the invention, themeasurements are taken at a plurality of measuring points and themeasured values are fed to a Computer in which comparison is made withfixed data of the casting material and of the plant. After a comparisonof this data is made, influences are exerted on the operations with theend results that the casting, feeding, cooling or forming operations areimproved. The evaluation of the results from such data processingdevices permits treatment of the complex individual influential factorsbetter than is done at the present time.

It is also of advantage that the measured values of several measuringpoints are transmitted to a single receiving station. The respectivemost accurate measuring quantity can be determined more easily and canserve as a selective value to regulate the main data decisively, such asfor the regulation of the casting velocity for example.

A device for carrying out the method of the invention providestemperature feelers on a cylinder which has means for connecting thesensors through a conducting zone to a transmitter which revolves withthe cylinder or to an electrical transmission device through anelectrical cable. The transmitters form, together with the receiversarranged in the control center of the plant, a transmission zone forcontrolling the plant operation. In its simplest form the deviceprovides a measuring and transmitting station and a receiving stationwith the associated regulating elements for the plant operation. Themeasuring and transmitting device comprises a cylinder with temperaturefeeler elements which are exposed at the surface thereof and which bearagainst the rod in alternate successions as the cylinder is rotated incontact with the rod which is being cast. The device providesinformation about the behavior of the temperatures in the cast rod whichis important for the course of the entire casting process. Theindividual cylinders may be arranged adjacent the continuous castingmold, before the feeding machine and before the rod forming unit. Thecurrent supply for the transmitter arranged within the cylinder iseffected by batteries which are also located within the cylinder and cancomprise for example rechargeable battery cells. In another embodimentof the invention the signals are transmitted by a wireless currentsupply system to all of the accumulators or contact elements which arearranged in the measuring cylinders for feed-- ing the transmitters.

In order to avoid loss of heat due to the contact of the measuringcylinder with the rod the measuring cylinders are advantageously made ofa material of varying thermal conductivity and the temperature feelersare embedded in materials of high thermal conductivity. The amount ofheat to be measured for the resulting temperature is measured thereforein the full heat current.

By using a rotating measuring feeler carrier element the measuringfeeler always moves away from the rod and touches the rod relativelybriefly. By arranging several temperature sensors around the peripheryof the rotating cylinder several temperature indications can be obtainedduring each rotation of the cylinder. The individual feelers can beconnected in dependence upon the position within the cylinder to anarcuate contact element which is in turn connected to a transmitterwhenever a temperature feeler is in the immediate proximity to the pointof contact. Such a measuring arrangement has a great advantage in thatthe measuring feelers themselves are subjected to great stress that theycan sense the temperature if they are only in contact with the measuringobject for a short period of time and permitted to cool OH to an extentthat there is no danger of destruction. In addition, there is noimpairment of this sensing of the temperature because an additionalmeasuring point which follows takes over the previously measured value.In this sense there is a division of the thermal load between theseveral temperature feelers and a division of the measuring work overthe existing number of temperature feelers. The apparatus also includesmeans for switching the connection of the plurality of temperaturesensors to the indicating device and to the transmitting means. Forexample, adjacent temperature feelers arranged around the circumferenceof the measuring cylinder are connected with each other by adifferential or compensation circuit so that the first measured valuecan already be picked up by the following temperature feeler. Theintroduction of the amount of heat that determines the temperature isalso facilitated by the fact that the measuring cylinder is providedwith projections like studs or fins for effecting the sensing of thetemperature.

Accordingly, it is an object of the invention to provide an improvedmethod of carrying out a continuous casting process which includesarranging a moving member in contact with the casting to continuouslysense the temperature of the exterior of the casting on at least onepoint along its path of movement, and transmitting the sensed values toa control station for use in controlling the conditions of continuouscasting.

A further object of the invention is to provide a device for sensing thetemperature of a continuously cast rod particularly a continuously caststeel rod which comprises a rotatably cylinder having a plurality oftemperature feelers arranged around the circumference thereof which areadapted to sequentially bear against the rod at a particular point alongits path of movement after casting, and wherein the cylinder containsmeans for transmitting the values of temperature which are sensed by theindividual feeler elements to a control station.

A further object of the invention is to provide a device for sensing thetemperature of a rod which is being continuously cast or one which hasvariations of temperature and constituency throughout its cross sectioncomprising a rotatable cylinder having a plurality of individual feelerelements projecting outwardly from the circumference thereof atcircumferentially spaced radial locations, arcuate contact means withinsaid cylinder arranged to connect the feeler elements the point ofphysical contact of the cylinder and the temperature feeler with thecasting rod to indicating and/or amplifying means and further totransmitting means for transmitting the temperatures to a remotelocation.

A further object of the invention is to provide a device for sensingtemperature of a obntinuously cast rod at some location in respect tothe continuous cast mold which is simple in design, rugged inconstruction, and economical to manufacture.

The various features of novelty which characterize the invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which there are illustrated and described preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a vertical cross sectional view of a rod which is beingcontinuously cast and having a measuring device associated therewithconstructed in accordance with the invention;

FIG. 2 is a view similar to FIG. 1 but showing a bent cast rod;

FIG. 3 is an enlarged partial cross sectional view of another embodimentof the invention; and

FIG. 4 is an electrical diagram for the electrical connection of thedevice indicated in FIG. 3.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to thedrawings in particular, the invention embodied therein in FIG. 1comprises a continuous casting mold 2 for the continuous casting of arod 1 which begins solidifying within the mold 3 to an extent such thatit begins forming a rod shell 3. The rod shell 3 increases, in theconventional cooling method for continuous casting operations,substantially uniformly up to a so-called sump tip 4 at which point therod is as sumed to be completely solidified. The inner liquid part orcore 5 of the rod 1 up to the sump tip 4 has thus a higher temperaturethan the rest of the rod so that the heat must be fed in large amountsfrom the core 5 through the rod shell 3.

Starting from a certain point of the rod, for example, in the range ofthe sump tip 4, the heat current decreases to such an extent that it canbe considered reduced with respect to the preceding points. After thesump tip 4, the rod is in the hot forming range in which deformationscan be safely effected.

In accordance with the invention means are provided for continuouslysensing temperature of the rod 1 at some point along its form tion afterit passes through the mold 2. In the embodiment illustrated in FIG. 1, ameasuring cylinder 6/ having several temperature sensors 7 which projectoutwardly from its periphery at circumferentially spaced radiallocations is mounted to rotate with its surface in direct contact withthe rod 1 at a location near feed rollers 40, 40. The temperature sensor7 engages into the surface of the rod 1 for the temperature sensingoperation and they are connected through lines 8 to a transmitter 9which transmits the measured values continuously or intermittently to areceiver (not shown). The transmitter 9 arranged within the cylinder 6rotates with the cylinder and in this embodiment it needs no meansconnecting it to a receiving devices but instead it operates on awireless or radial principle.

In the embodiment indicated in FIG. 1, the measuring cylinder 6 is incontact with the rod only at the point 10 and in the range of the sumptip 4. Several such measuring cylinders 6' and 6", for example, can beprovided at different cross sectional sides such as the front side 11 orthe left side 12 as shown in FIG. 1 and also at diverse locations suchas adjacent the mold 2 and beyond the rod feeding means 40, 40 at alocation roller 6" where the rod is to be formed by forming rollers (notshown). The temperature information sensed may be transmitted through adirect electrical connection such as slip ring 42 and pick up 44 andcable 46 to a control station 48.

FIG. 2 shows the same arrangement of a temperature sensing cylinder 6"in respect to a rod 1' which is bent during the continuous castingprocess and directed around through a curve as indicated. The measuringcylinder 6' which is rotatably mounted on a movable rod 41 can thereforebe applied in the range of the sump tip 4 whether in a vertical feedarrangement or in an arcuate feed arrangement for the rod' which isformed. Such a temperature sensing arrangement is particularly suitedfor setting the conditions for the subsequent deformation of the rodeither directly in the range of the sump tip 4 or thereafter. Theinvention is particularly suitable therefore in combination with rodforming stands of any type (not shown). The values which are transmittedby the transmitter 9 to the receiver 48 at the control station (FIG. 1)thus serve for example, to control the adjusting movement of the formingrolls of a forming stand or of a high forming unit such as a stretchforming machine. In addition, of course the valuescan be used forcontrolling the feeding of the material to the mold 2 and the rate ofadvance of the rod as it is formed.

In the embodiment illustrated in FIG. 3, there is provided a temperaturesensing cylinder assembly generally designated 6" which includes aplurality of temperature sensors 7"" comprising thermocouples arrangedinside the cylinder 13 having one connection 14 applied to a commoncontact ring 15 so that the maximum temperature value which is measuredat the contact point 10 can always be taken from this ring 15.

The same measuring cylinder 6" can also be designed with a transmitter9"" connected to receive the measuring values of the temperature sensors7" only when the contact ring 15 with the respective temperature feeler7"" is just opposite the contact device 16 which extends through anarcuate range on either side of the contact point 10. The temperaturesensor 7"" also includes another contact 8" which extends back to thecontact ring 17 which is connected to a power source 18 and to thetransmitter 9"".

As indicated in the electrical diagram shown in FIG. 4, both the feedlines 8" and the feed lines 14 from the temperature 7" are conducted toa compensation resistance or variable resistance 19 over which flows thecurrent of the power source 18. The power source 18 also feeds to anamplifier which sends its outerput signals to the transmitter 9"". Thetransmitter 9"" in turn transmits the temperature information to areceiver 48' at a control station. The information is put into acomputer 50 for comparison with a control sample and control signals aresent out from the computer to an operational control 52 for changing theoperation conditions are necessary. The compensation resistance' 19 isso connected that when it is set correctly no current has to flow in thetemperature feeler circuit. The temperature indicated by the temperaturefeeler 7 can thus be read immediately on the resistance 19 without acorresponding calibration of the apparatus.

Normally, when the sensing cylinder 6 rolls off the hot cast rod 1 thereis a possibility that the temperature fluctuations along thecircumference of the rod adversely influence the measuring result. Thecompensating circuit shown in FIG. 4 is provided to eliminate this byuse of the compensating resistance which is set to permit reading of anaverage temperature value as it appears between two circumferentialpoints of the measuring cylinder. The resistance 19 may be set so thatthere is no current flow in the circuit between the energy source 18 andthe temperature sensor 7"".

What is claimed is:

1. A device for continuously sensing the temperature of a metal rod asthe rod is being continuously cast, comprising a rotatable cylinderhaving at least one temperature sensing element on its periphery whichpenetrates the rod being continuously cast, said cylinder with itstemperature sensing element being rotatable upon movement of the rod toperiodically position the temperature sensing element at a location tosense the temperature of said rod, and transmission means carried bysaid cylinder and connected to said temperature sensing element fortransmitting sensed temperature information to a remote location.

2. A device, according to claim 1, wherein said transmission meanscomprises an electrical transmitting device having a cable extending toa remote station.

3. A device, according to claim 1, wherein said transmission meanscomprises a radio transmitter.

4. A device, according to claim 1, including a power supply in saidcylinder electrically connected to said temperature sensing element, anelectric transmitter connected to said power supply and to said sensingelement and comprising said transmission means.

5. A device, according to claim 1, wherein said measuring cylinder ismade of materials of high and low thermal conductivity said temperaturesensing element being imbedded in a material of high thermalconductivity adjacent the periphery of said cylinder.

6. A device, according to claim 1, including a plurality of temperaturesensing elements arranged around the periphery of said cylinder and acontact means within said cylinder electrically connected to saidtransmission means and to said temperature sensing elements and beingeffective to connect only those sensing elements adjacent the point ofcontact of said cylinder with said rod to said transmission means.

7. A device, according to claim 1, wherein sald measuring cylindertemperature sensing element includes a plurality of projecting elementsfor penetrating into the cast rod.

8. A device according to claim 1, wherein said rod is continuously castin a continuous casting mold and including a plurality of cylindersarranged along the length of said rod each having a temperature sensingelement, and rod feeding means for feeding said continuous cast rod awayfrom said mold, and wherein at least one of said cylinders is adjacentsaid continuous casting mold and one is adjacent said rod feeding means.

9. A device for continuously sensing the temperature of a continuouslymoving metallic body, comprising a rotatable cylinder having on itsperiphery a plurality of temperature sensing elements which penetratesaid body, said cylinder with its temperature sensing elements beingrotatable upon movement of the body to periodically position thetemperature sensing elements at locations to sense the temperature ofsaid body, and transmission means carried by said cylinder and connectedto said temperature sensing elements for transmitting sensed temperatureinformation to a remote location.

1. A device for continuously sensing the temperature of a metal rod asthe rod is being continuously cast, comprising a rotatable cylinderhaving at least one temperature sensing element on its periphery whichpenetrates the rod being continuously cast, said cylinder with itstemperature sensing element being rotatable upon movement of the rod toperiodically position the temperature sensing element at a location tosense the temperature of said rod, and transmission means carried bysaid cylinder and connected to said temperature sensing element fortransmitting sensed temperature information to a remote location.
 2. Adevice, according to claim 1, wherein said transmission means comprisesan electrical transmitting device having a cable extending to a remotestation.
 3. A device, according to claim 1, wherein said transmissionmeans comprises a radio transmitter.
 4. A device, according to claim 1,including a power supply in said cylinder electrically connected to saidtemperature sensing element, an electric transmitter connected to saidpower supply and to said sensing element and comprising saidtransmission means.
 5. A device, according to claim 1, wherein saidmeasuring cylinder is made of materials of high and low thermalconductivity said temperature sensing element being imbedded in amaterial of high thermal conductivity adjacent the periphery of saidcylinder.
 6. A device, according to claim 1, including a plurality oftemperature sensing elements arranged around the periphery of saidcylinder and a contact means within said cylinder electrically connectedto said transmission means and to said temperature sensing elements andbeing effective to connect only those sensing elements adjacent thepoint of contact of said cylinder with said rod to said transmissionmeans.
 7. A device, according to claim 1, wherein said measuringcylinder temperature sensing element includes a plurality of projectingelements for penetrating into the cast rod.
 8. A device according toclaim 1, wherein said rod is continuously cast in a continuous castingmold and including a plurality of cylinders arranged along the length ofsaid rod each having a temperature sensing element, and rod feedingmeans for feeding said continuous cast rod away from said mold, andwherein at least one of said cylinders is adjacent said continuouscasting mold and one is adjacent said rod feeding means.
 9. A device forcontinuously sensing the temperature of a continuously moving metallicbody, comprising a rotatable cylinder having on its periphery aplurality of temperature sensing elements which penetrate said body,said cylinder with its temperature sensing elements being rotatable uponmovement of the body to periodically position the temperature sensingelements at locations to sense the temperature of said body, andtransmission means carried by said cylinder and connected to saidtemperature sensing elements for transmitting sensed temperatureinformation to a remote location.